University Chemical Laboratories, Cambridge CB2 1EW, United Kingdom.
Proc Natl Acad Sci U S A. 2014 Jan 14;111(2):617-22. doi: 10.1073/pnas.1319599111. Epub 2013 Dec 27.
When structures that interconvert on a given time scale are lumped together, the corresponding free-energy surface becomes a function of the observation time. This view is equivalent to grouping structures that are connected by free-energy barriers below a certain threshold. We illustrate this time dependence for some benchmark systems, namely atomic clusters and alanine dipeptide, highlighting the connections to broken ergodicity, local equilibrium, and "feasible" symmetry operations of the molecular Hamiltonian.
当在给定时间尺度上相互转换的结构被归并在一起时，相应的自由能表面就成为观察时间的函数。这种观点等同于将通过低于某个阈值的自由能势垒连接的结构进行分组。我们以一些基准系统，即原子团簇和丙氨酸二肽为例，说明了这种时间依赖性，突出了与破局遍历性、局部平衡和分子哈密顿量的“可行”对称操作的联系。
